HP 54645D 100-MHz Mixed Signal Oscilloscope

I got an old HP mixed signal oscilloscope HP54645D. This is over 20 years old test instrument with 7″ CRT display. The 54645D is a 100 MHz, 2+16 channel Mixed Signal Oscilloscope from Agilent. Measure voltage or current signals over time in an electronic circuit or component to display amplitude, frequency, rise time, etc. Applications include troubleshooting, production test, and design.


The HP 54645D (also known as Keysight 54645D) mixed-signal oscilloscope was designed for embedded systems developers. This Mixed-signal oscilloscope focuses on 8-bit microcontroller applications was released to market in 1996. This product was discontinued in March 2001.

It was specifically designed to cost-effectively address the testing and troubleshooting needs of the many engineers designing with 8-bit microcontrollers, but was powerful enough also for many 16-bit embedded applications.

The Keysight 54645D 100-MHz 200-MSa/s Mixed Signal Oscilloscope seamlessly integrates logic channels into an oscilloscope to offer new measurement capability for designers of combined analog and digital systems. Analog and digital on one display, aligned in time, to help you isolate cause and effect in complex circuits.

The 54645D was selling for under $5,000 ($4,995 stock), which was cheap at the time when you consider what features it offers.

The HP 54645D is a two-channel, deep-memory oscilloscope integrated with a 16-channel logic analyzer. It features the ability to trigger on any or all of its 18 channels and to observe and measure the relationship of the analog and logical operations of a circuit under test on a single display screen.



Scope Channels: Ch. 1 and Ch. 2. 
Bandwidth (3dB): dc to 100 MHz @ >= 10 mv/div (> 75 Mhz @ < 10 mv/div), ac Coupled: 1.5 Hz to 100 MHz. 
Rise Time (calculated): ~ 3.5 ns @ > 10 mv/div (< 4.6 ns @ < 10 mv/div). Input Resistance: 1 Mohm. 
Input Capacitance: ~13 pF. 
Maximum Input: 400 V (dc + peak ac). Range: 1 mV/div to 5 V/div. 

Digital channels: 16 channels (0-15) in two pods of 8 channels each 
Maximum Input Voltage: ± 40 volts peak. 
Threshold Range: ± 6.0 volts in 50 mV increments. 
Threshold Accuracy: ± (100 mV + 3% of threshold setting). 
Sweep Speeds: 50 s/div to 5 ns/div main and delayed. 
Accuracy: ± 0.01%. Horizontal Resolution: 40 ps. Trigger Modes: Auto, Autolevel, and Normal. 
Holdoff: ~ 200 ns to ~ 25 seconds. 
Polarity: Rising or falling. 
Minimum Pulse Width Setting: 8 ns. 
Maximum Sampling Rate: 400 MSa/s on one pod, 200 MSa/s on two pods. Maximum Memory Depth: 2 MB samples per channel on one pod, 1 MB samples when both pods are used.

Display: 7-inch raster monochrome CRT. 

The two scope channels of the HP 54645D are each 100 MHz and 200 megasamples/s, and feature 1 Mbyte of memory. The logic-analysis channels run at 400 Msamples/s and 2 Mbytes of memory on eight channels, and 200 Msamples/s and 1 Mbyte of memory on 16 channels.The scope supports simple edge, pattern, and advanced triggering capabilities, including a glitch triggering feature.

Because the MSO is an two channel digital oscilloscope, you works for everyday use with its simple edge triggering. This has the familiar scope triggering mode and it is the one that will solve most of problems that you have with electronics circuits. In addition to analog channels, you can view the 16 digital states and use them as triggering source.
You can trigger on a rising or falling edge on any of the MSO’s 18 input channels. Pattern triggering is provided to allow you to set up a pattern of high, low and don’t-care levels across any or all of the MSO’s 18 channels.

The 54645 was the first of the digital oscilloscopes with MegaZoom so it has 4 megapoints memory both on analog AND digital combined. MegaZoom technology that is a multiprocessor/parallel-processing architecture that enables the HP 54645D to combine the deep memory capability associated with some high-end DSOs with the ease-of-use, high update rates, and responsiveness usually found only traditionally in analog scopes. Megazoom is , apart from the large memory, basically a huge resampling ASIC that resamples the ‘slot’ you define in the memory and creates a 540 pixel wide image to screen. I have to admit that MegaZoom works well.

While the HP 54645D is not the first instrument to combine oscilloscope and logic-analysis capabilities, its ease of use, versatility, and price combine to set a new standard.

Digital Oscilloscope Set Up and Tutorial using HP 54645D Digital Storage Oscilloscope video shows how to set up and use the HP 54645D digital oscilloscope.

HP 54645D Pushed to the MAX! video demonstrates how responsive and capable a vintage (1998) digital HP scope (HP 54645D) is. This video also demonstrates FFT function from the Measurement module (that I don't have).

There is a "easter egg" game in this oscilloscope. It can be started by pressing first "Print Utility" and then two buttons below screen together (buttons 2 and 3 from left to right).


HP 54645D Manuals

Keysight product page with manual downloads



Mixed-signal oscilloscope focuses on 8-bit microcontroller applications
Posted on January 1, 1997 by Electronic Products

Old logic analyzer and probe cables

Keysight (Agilent) 54645D CALIBRATION and Keysight (Agilent) 54645D REPAIR

54645D 100-MHz 200-MSa/s Mixed Signal Oscilloscope

Should I sell my 54645D for a new Rigol?

HP54645D print screen via RS232

Playing Tetris On An Oscilloscope

1 Comment

  1. Tomi Engdahl says:

    The “easter egg” game started in the same way as Tetris on some other oscilloscopes in this product series


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